Single-use containers, such as bioreactors are useful for generating and supporting biological reactions for any number of purposes. The life sciences industry is moving from large, capital-intensive facilities made of stainless steel with large clean-in-place (CIP) infrastructure to smaller facilities that use polymeric bags or containers functioning as bioreactors. The bioreactor bag is used once and then discarded. The single-use bioreactor technique significantly reduces the capital cost of the plant. For example, in existing facilities that use stainless steel CIP infrastructure, up to 90% of the cost of operating the facility may be due to the clean-in place infrastructure, including very high end instrumentation designed to withstand a steam cleaning cycle. By moving to disposable, single-use bioreactor bags, the CIP portion of the capital can be eliminated and the facility can be more flexible and much smaller, which, in turn, allows the production of smaller batches that are needed for more targeted drug therapies and other smaller-scale applications.
As pharmaceutical manufacturers change over from large stainless steel process vessels to smaller-volume, pre-sterilized, disposable plastic bag systems, there is a need to measure process variables in these systems in order to control the growth environment and subsequent processes. Typically, pharmaceutical manufacturers and the life science industry, in general, have used relatively inexpensive sensors and relatively crude methods from fluid isolation, such as silicone gel. These methods can lead to inaccurate measurements, which are generally unacceptable to the life sciences industry for supporting the various biological reactions.